Billys are gas assisted shocks - nitrogen at high pressure helps the oil when it's getting hammered. The struts are put in upside-down - the thick part of the strut uppermost, and the thinner inner rod is screwed through the base of the housing, with a locknut. Which always rusts up solid.
The capri struts are best used to build from these days - they have removeable steering arms, and as mentioned are 1 inch shorter than the escort ones. I don't think they were wedged as standard, but it's pretty simple to do.